Sildenafil, widely recognised by the brand name Viagra, is a phosphodiesterase type 5 (PDE5) inhibitor prescribed for erectile dysfunction and pulmonary arterial hypertension. Whilst generally well-tolerated, some patients wonder: does sildenafil give you heartburn? The answer is yes—dyspepsia, including heartburn symptoms, is a documented adverse effect occurring in approximately 3–7% of users. This article explores why sildenafil may trigger heartburn, how common this side effect is, practical management strategies, and when to seek medical advice. Understanding these aspects helps patients use sildenafil safely whilst minimising gastrointestinal discomfort.

Can Sildenafil Cause Heartburn?

Yes, sildenafil can cause dyspepsia (indigestion), which often includes heartburn symptoms. Sildenafil, commonly known by the brand name Viagra, is a phosphodiesterase type 5 (PDE5) inhibitor primarily prescribed for erectile dysfunction and pulmonary arterial hypertension. Whilst it is generally well-tolerated, gastrointestinal symptoms including indigestion, heartburn, and acid reflux are documented adverse effects in clinical trials and post-marketing surveillance data.

One possible mechanism by which sildenafil may trigger heartburn relates to its effect on smooth muscle. Sildenafil works by inhibiting the PDE5 enzyme, which leads to increased levels of cyclic guanosine monophosphate (cGMP) in smooth muscle cells. This causes vasodilation in blood vessels, which is the intended therapeutic effect. Some studies suggest this smooth muscle relaxation may potentially affect the lower oesophageal sphincter—the muscular ring that prevents stomach acid from flowing back into the oesophagus.

If the lower oesophageal sphincter relaxes inappropriately, gastric acid can reflux into the oesophagus, causing the burning sensation characteristic of heartburn. This effect is typically temporary and coincides with the period when sildenafil is active in the body, usually within a few hours of taking the medication. The Medicines and Healthcare products Regulatory Agency (MHRA) lists dyspepsia (indigestion) as a common side effect of sildenafil in the Summary of Product Characteristics.

It is important to note that whilst sildenafil can cause heartburn symptoms, not everyone who takes the medication will experience this side effect. Individual susceptibility varies considerably, and those with pre-existing gastro-oesophageal reflux disease (GORD) may be more prone to experiencing heartburn when taking sildenafil.

How Common Is Heartburn When Taking Sildenafil?

Dyspepsia (indigestion, which includes heartburn symptoms) is classified as a common side effect of sildenafil, occurring in approximately 1 in 10 to 1 in 100 people who take the medication. According to clinical trial data submitted to regulatory authorities, dyspepsia was reported in roughly 3–7% of participants taking sildenafil for erectile dysfunction, compared to 1–2% in placebo groups.

The frequency of heartburn symptoms appears to be dose-dependent, with higher doses of sildenafil (100 mg) associated with a greater incidence of gastrointestinal side effects compared to lower doses (25 mg or 50 mg). This dose-response relationship supports the pharmacological mechanism whereby greater PDE5 inhibition leads to more pronounced effects.

Several factors may influence an individual's likelihood of experiencing heartburn with sildenafil:

• Pre-existing GORD or hiatus hernia – Patients with underlying reflux conditions are more susceptible

• Concurrent medications – Some medications may increase reflux risk (note: nitrates and nitric oxide donors are absolutely contraindicated with sildenafil)

• Timing of food intake – Taking sildenafil on a full stomach, particularly after fatty or spicy meals, may increase heartburn risk

• Alcohol consumption – Alcohol can relax the lower oesophageal sphincter and exacerbate reflux symptoms

• Body position – Lying down shortly after taking sildenafil may facilitate acid reflux

• Other factors – Obesity and smoking can also contribute to reflux symptoms

Most cases of sildenafil-associated heartburn are mild to moderate in severity and resolve spontaneously without requiring discontinuation of treatment. However, persistent or severe symptoms warrant medical review to exclude other causes and consider management strategies or alternative treatments.

Managing Heartburn While Using Sildenafil

For patients experiencing heartburn with sildenafil, several practical strategies can help minimise symptoms whilst maintaining treatment efficacy. These approaches range from simple lifestyle modifications to pharmacological interventions, and should be tailored to individual circumstances.

Lifestyle and timing modifications can significantly reduce heartburn risk:

• Take sildenafil on an empty or light stomach – Avoid taking the medication immediately after large, fatty, or spicy meals, which can delay absorption and increase reflux risk

• Remain upright after dosing – Stay sitting or standing for at least 30–60 minutes after taking sildenafil to reduce the likelihood of acid reflux

• Avoid trigger foods and beverages – Limit alcohol, caffeine, chocolate, citrus fruits, and tomato-based products around the time of taking sildenafil

• Avoid grapefruit juice – This can increase sildenafil blood levels and potentially worsen side effects

• Elevate the head of the bed – If symptoms occur at night, raising the head end by 15–20 cm can help prevent nocturnal reflux

Pharmacological management may be appropriate for persistent symptoms:

• Antacids containing aluminium hydroxide, magnesium hydroxide, or calcium carbonate can provide rapid symptomatic relief by neutralising stomach acid

• Alginates (such as Gaviscon) form a protective barrier on top of stomach contents and may be particularly helpful for reflux symptoms

• Proton pump inhibitors (PPIs) such as omeprazole or lansoprazole reduce gastric acid production and are available over the counter or on prescription. If using regularly, a 4-week trial with review is recommended, with step-down to the lowest effective dose

Dose adjustment represents another strategy. If heartburn is troublesome, speak with your prescriber about trying a lower dose of sildenafil (e.g., reducing from 100 mg to 50 mg), which may reduce side effects whilst maintaining adequate therapeutic effect. The NICE Clinical Knowledge Summary on erectile dysfunction supports individualised dose titration based on efficacy and tolerability.

Remember: Sildenafil must never be taken with nitrate medications (such as GTN spray or tablets for angina) or recreational 'poppers' as this combination can cause a dangerous drop in blood pressure. Use caution if taking alpha-blocker medications, as the combination may increase the risk of dizziness.

When to Seek Medical Advice About Sildenafil Side Effects

Whilst mild heartburn is a recognised and generally manageable side effect of sildenafil, certain symptoms warrant prompt medical attention. Understanding when to contact your GP or seek urgent care is essential for patient safety.

Contact your GP or pharmacist if:

• Heartburn persists despite simple measures or becomes progressively worse

• You experience difficulty swallowing (dysphagia)

• Heartburn is accompanied by unexplained weight loss

• You develop persistent nausea or vomiting

• Symptoms significantly impact your quality of life or ability to take the medication as prescribed

• You require regular use of antacids or other medications to control symptoms

These features may indicate more significant gastro-oesophageal pathology requiring investigation. NICE guidance recommends that patients with dysphagia at any age, or those over 55 with persistent dyspepsia plus weight loss, should be referred urgently (within two weeks) to exclude serious conditions.

Seek immediate medical attention (call 999 or attend A&E) if you experience:

• Chest pain – Particularly if severe, crushing, or radiating to the jaw, neck, or arm, as this may indicate cardiac pathology rather than simple heartburn

• Severe abdominal pain – Especially if sudden onset or accompanied by rigidity

• Vomiting blood (haematemesis) or passing black, tarry stools (melaena) – These indicate gastrointestinal bleeding

• Prolonged erection – An erection lasting more than 4 hours (priapism) requires emergency treatment

• Sudden vision changes or loss – This could indicate a rare but serious eye complication

• Sudden hearing loss or ringing in ears – A rare but significant adverse effect

• Severe allergic reactions – Such as facial swelling, difficulty breathing, or widespread rash

It is crucial to distinguish between heartburn and cardiac chest pain, particularly as sildenafil is often prescribed to men with cardiovascular risk factors. If there is any doubt about the nature of chest discomfort, err on the side of caution and seek urgent medical assessment. For urgent but non-emergency concerns, NHS 111 can provide advice.

Additionally, inform all healthcare professionals about your sildenafil use, as it has important interactions with nitrate medications commonly used for angina. If you suspect you're experiencing side effects from sildenafil, you can report them through the MHRA Yellow Card Scheme.

Frequently Asked Questions